Boron distributions in individual core-shell Ge/Si and Si/Ge heterostructured nanowires
Boron distributions in individual core-shell Ge/Si and Si/Ge heterostructured nanowires
复制标题
单个核壳 Ge/Si 和 Si/Ge 异质结构纳米线中的硼分布
作者：
B. Han;Y. Shimizu;J. Wipakorn;K. Nishibe;Y. Tu;K. Inoue;N. Fukata;Y. Nagai
Ge/Si和Si/Ge核壳纳米线(NWS)在各种器件中具有很大的应用潜力。由于Ge/Si和Si/Ge核壳纳米线中的杂质分布强烈影响其电学性质，进而影响器件的性能，因此迫切需要关注这一问题。本文用原子探针层析技术研究了两种原子核中最重要的杂质之一--硼(B)的分布。B原子被掺杂到Ge/Si和Si/Ge核壳纳米晶的硅区。结果表明，在Ge/Si核壳纳米晶的硅壳中，B原子呈随机分布。另一方面，在Si/Ge核壳纳米晶中，B的分布依赖于生长温度和B2H6流量。随着生长温度的升高和B2H6通量的增加，B原子堆积在硅芯的外部区域。然而，在降低生长温度和B2H6流量后，观察到B原子在硅芯中呈随机分布。
Ge/Si and Si/Ge core–shell nanowires (NWs) have substantial potential for application in many kinds of devices. Because impurity distributions in Ge/Si and Si/Ge core–shell NWs strongly affect their electrical properties, which in turn affect device performance, this issue needs urgent attention. Here we report an atom probe tomographic study of the distribution of boron (B), one of the most important impurities, in two kinds of NWs. B atoms were doped into the Si regions of Ge/Si and Si/Ge core–shell NWs. It was found that the B atoms were randomly distributed in the Si shell of the Ge/Si core–shell NWs. In the Si/Ge core–shell NWs, on the other hand, the B distributions depended on the growth temperature and the B2H6 flux. With a higher growth temperature and an increased B2H6 flux, the B atoms piled up in the outer region of the Si core. However, the B atoms were observed to be randomly distributed in the Si core after decreasing both the growth temperature and the B2H6 flux.